Project Summary ? Experimental Core The Experimental Core at the West Coast Metabolomics Center for Compound Identification (WCMC) is committed to the overall goals of the NIH Common Fund Metabolomics Initiative and specifically aims to greatly improve small molecule identifications. The Experimental Core is led by the WCMC director Prof. Fiehn with close support from several experienced mass spectrometrists, chromatography experts and database programmers. The following specific aims will be covered: 1) The use of deuterium exchange, specific functional group derivatization and high resolution chromatography/mass spectrometry to deduce substructural features to drastically limit the number of false isomers. The information will be incorporated into a compound identification pipeline and software tools developed in close collaboration with the Computational Core. 2) The development of a large open access reference library for LC-MS/MS and GC-MS retention times and mass spectral data. These databases serve as backbone for our LC-BinBase database that will employ high quality MS/MS spectra through our MS-DIAL software and link it to biomedical metadata through our miniX study design database. Such information will be used for the detection of presence and intensity of unknowns that can be prioritized using BinVestigate across a large diversity of biological studies. 3) The experimental validation of computational methods and confirmation of novel metabolites, the benchmark of WCMC and consortium capabilities and acquisition of data through suitable metabolomic reference studies and blinded sets of chemical standards.